From the prior art, it is known a device for water filtering (U.S. Pat. No. 5,002,665, published on 26 Mar. 1991, IPC B01D24/00), the device includes a filtering insertion (1) filled with a filtering material and made in the form of a bowl which can be closed with a lid (3) having outlet openings (5) in its bottom part, the openings being closed from above with a mesh (9) of low-melting plastic fibers which can be welded to the bottom (pages 1, 2 of the specification; FIGS. 1, 2). This device is difficult enough to produce and has a small flow area, which results in decreasing filtration speed.
It is known a filtering unit for liquid purifying, the filtering unit comprises a case (2) made in the form of a bowl with side walls and a bottom (6) with outlet openings (9), and a lid with holes for liquid inlet. A granulated filtering material is placed in the case. To prevent the filtering material to get into purified liquid, a mesh (8) made in the form of a flat disk and welded to the bottom is placed between said material and the bottom. The mesh is made of a nonwoven fabric, for example, polypropylene (page 1 of the specification; FIG. 2), (U.S. Pat. No. 5,049,272, published on 17 Sep. 1991, IPC B01D24/14). At production of said unit it is necessary additionally to fix the mesh to the unite basis.
From the U.S. Pat. No. 6,012,232 published on 11 Jun. 2000, IPC F26B19/00, it is known a filtering unit filled with a filtering material, the filtering unit comprises side walls, a lid and a bottom with outlet openings closed with a mesh. The material, which the mesh is made of, comprises two types of fibers connected together: hydrophilic and hydrophobic fibers (page 3 of the specification). Due to a small flow area, it is impossible to achieve high filtration speed, which decreases operating performances of a product.
The closest analogue of the present invention is a filtering cartridge (1) known from the U.S. Pat. No. 6,099,728, published on 8 Aug. 2000, IPC B01D27/02, wherein the filtering cartridge filled with a granulated filtering material and made in the form of an open bowl that can be closed with a lid, and has side walls (3) and a bottom (1) with outlet openings (2) closed with a fabric insertion (12) having a plastic frame (11) (page 2 of the specification, FIGS. 1, 2), wherein the size of cells is from 50 to 300 microns, preferably 80-200 microns (page 1 of the specification). The outlet openings located in the bottom of said cartridge have a restricted flow area, which leads to decreasing filtration speed, i.e. to deterioration of operating performances of a product. At production of said cartridge, a separately dedicated stage of production is required, in which the insertion with a plastic frame is formed. The already produced insertion is used at manufacture of the cartridge itself by a method of injected moulding. Multiple stages of production process complicate techniques of producing a filtering cartridge. Methods of producing filtering means or their elements from plastics which are known from the prior art are generally based on a method of injected moulding under pressure. However, the main problem of producing filtering means arises at use of fiber materials, for example, nonwoven materials with a small fiber diameter, for example, 2-20 microns. The possibility of using said materials as a part of filtering devices allows applying a smaller sorbent in liquid purifying means, for example, a powder-like filtering material with the size of particles less than 50 microns, which in turn leads to heightening purification degree of filtered liquid. However, at an automized piece cutting from such materials, it is necessary to ensure that clearances in a cutting stamp is much less than diameters of fibers, which is not possible in the prior art. Other methods of obtaining such products consist in using clinking dies, ultrasonic and laser cutting and cutting with a hot instrument. All these methods do not ensure steady automatic operation.
The closest analogue for a method of producing a filtering cartridge according to the present invention is a method of producing a shell or a part of fashioning with directly cast fastening element known from the U.S. Pat. No. 6,887,413, published on 3 May 2005, IPC B29C45/14, comprising the steps of: placing a blank which represents a decorative part with a layer of wood veneer, or a part of sheet metal, or a nonwoven coverage on a substrate, etc., in at least a split mould for moulding under pressure, closing a mould and thus providing excising (cutting down) of a piece from a blank to reach an exact form, than filling a shaping cavity of the mould with a melted composition for casting by an injection method under pressure and, after hardening of a composition, extracting a product from the mould. In said method, the use of fiber materials with a small fiber diameter as a blank leads to a problem of cutting down of the blank.